Facing membrane for sound-absorbing materials



H. F. WEISS 1,785,507

Dec. 16, 1930.

FACING MEMBRANE FOR SOUND ABSORBING MATERIAL Filed Jan. 21, 1928 w jiowa aolf we Patented 16, 1930 NI-ran s'rATEs PATENT OFFICE HOWARD I. WEISS, OF MADISON, WISCONSIN, ASSIGNOR T0 C. I. BURGESS LABORA- TORIES, INC., OF MADISON, WISCONSIN, A CORPORATION OF DELAWARE FACING MEMBRANE FORtSOUND-ABSORBING MATERIALS Application filed January 21, 1928. Serial No. 248,528

This invention relates to improvements in facing membranes for sound-absorbing materials, such as are used on walls, ceilings and like.

It is an object of my'invention to provide a woven fabric havin a pleasing appearance which may be used or a facing membrane for sound-absorbing materials and which out clogging the interstices or apertures, whereby the sound reaches the sound-absorbing material. It is a further object of my invention to provide a fabric membrane which is stifi enoughand does not sag perceptibily when used to cover sound-absorbing materials mounted on ceilings. Other objects will become apparent from the specification and drawings wherein;

Fi 1 shows one type of my improved m mem rane;

Fig. 2 is a cross-section, somewhat enlarged of the thread used in Fig. 1;

I Fig. 3 shows another type of membrane;

.Fig. 4 is a cross-section of the pairs of I 1 threads used gthreads of Fig. 3 when subjected to heavy .pressure; 7

Fig. 6, 7 and 8 illustrate alternative methao' ads of installing the membrane in acoustical treatments.

In the acoustical treatment of walls and ceilings of rooms and auditoriums it is thegeneral practice to mount a sound-absorbing material, such as hairfelt, balsam-wool, and the like on the wall or ceiling and face this treatment with a covering membrane which rotects the sound absorber and is capable of eing decorated. In the past these membranes have been made'of cheesecloth, burlap, and similar woven fabrics. These fabrics give excellent results when first installed. However, they soon become dirty and it is practically impossible to wash them while they are on the wall or ceiling. It may be possible todecorate or redecorate them vonce or twice if care is used in applying the decorative material, but the fabrlc soon becomes clogged with the paint or other decorative 50 material and as a result the passage of sound may be painted or otherwise decorated with- Fig. .5 is a cross-section of the pairs of.

apertures are formed in the finished fabric,

is suitable for covering sound-absorbing ma- I terials and overcomes the objections to cheesecloth, burlap and the like. .A material which is satisfactory and cheap is a fabric woven from paper threads, as suchpa er threads are practically free from fuzz. ther fuzz-free materials may be used however. A narrow cut paper strip, especially when made of tough stock such as kraft, when twisted. fdrms a tough thread or string 10, having a smooth surface free from fuzzand which has a stiffness which makes it especially suitable for a covering membrane. Such a paper thread may be rolled or pressed into a fiat string as shown in cross section in 2. The paper thread or other fuzzefree material is woven into -a fabric having apertures formed therein b the weaving as shown in Fig. 1. This is one by keeping the threads of either or both the warp and woof separated a suitable distance during the weaving. Holes 1/32" square or larger are suitable. Although single threads may compose the warp and woof strands these should be at least from 3/128" to 1/32" in diameter so that the fabric has some body. I prefer to use a much heavier thread which is flattened to'the shape shown in Fig. 2. Such a paper thread after flattening may be about 1/64." x 1/16 in cross section. A fabric woven from this flattened thread with apertures at least 1/32 square has a body and stiffness which is de-' sirable as will be explained hereinafter.

In another modification as shown in Fig.

3, the separate strands of the Warp and wool? are composed of two or more parallel threads 11 shown in cross section in Fig. 4: and Woven to leave apertures at least 1/32" square. The finished fabric may be passed between squeeze rolls to flatten out thethrea'ds to some extent as shown in Fig.5, thereby giving the fabric a smooth appearanceand giving a final result closely resembling that obtained with the single flattened thread. The finished fabric may be used as a membrane for soundabsorbing material as shown in Fig. 6 in strips, as shown at the left hand end, or by the various other methods known to those skilled in the art. In another method of in stalling the treatment, the furring strips may be dispensed with and the material fastened directly to the walls or ceiling.

The apertures in the fabric allow the sound to pass into the sound-absorbing material 14. An acoustical facing membrane made in this manner has a surface which may be painted from time to time without danger of closing the apertures if ordinary care is used and especially if'a low viscosity paint is used. The surface, being smooth and free from fuzz, may be washed and cleaned without removing the material from the walls or ceiling.

Since paper is subject to humidity it is,

desirable to protect it as much as possible. It is also desirable to further stiffen the fabric sufliciently, so that it will not sag between supports, thereby improving its appearance.

I accomplish this by dipping the woven fabric into, or otherwise treating it with a colloidal sizing material, such as hide-stock glue, agar-agar, a phenolic condensation product, Duco and the like. These must be of such consistency as not to close the apertures. The sizing coats the threads and in accordance with the characteristic effect of a colloid upon fibrous material, shrinks and stiffens the fabric, thereby preventing sagging and the absorption of moisture. By stiffening the woven fabric in this manner it is possible to preform it into shallow panshaped units 16, which maybe handled without danger of collapsing, as shownin Fig. 7 Such pans, made of stiffened fabric, may be used with suitable lengths of furring strips, inch as shownin Fig. 6 or the frame 17 of The glue may be waterproofed by means of dichromate as is well known to those skilled in the art. Colors may also be incorporated in the stiffening substance. It is also possible to coat and stiffen the fabric with metals, as by electroplating as practiced in the galvano-plastic art or by the Schoop v process of spraying, whereby-a thin adherent metallic coating is formed on textile or paper fabrics without injury to the fabric. The

metallic coating has obvious advantages such as added stiffness and fire rce. Such a metallized fabric may be readily cleaned as well as a fabric, the threads of which consist of metal strands.

'The sound absorbing material in the form of pads, as shown in Fig. 6, may rest within the stiffened fabric pans and be supported thereby, or they maybe secured to the ceiling or wall in any convenient manner, as for example by means of glue and in some cases a 2. A shallow, pan-like facing unit for sound-absorbing material comprising a membrane of paper-thread fabric, said fabric being stiffened sufficiently to retain said panshape by means of a colloid and woven to leave apertures therein.

3. A sound-absorbing construction for walls and ceilings comprising sound-absorbing material associated therewith and a decoratable facing membrane substantially concealing said sound absorbing material and consisting of woven threads of nonfuzzy material, partially flattened and spaced apart to leave substantial openings for the penetration of the sound.

. 4. A sound absorbing construction for walls and ceilings comprising sound-absorbing material associated therewith and a decoratable facing membrane consisting of woven strands spaced apart to leave substantial openings for the penetration of sound, said strands each comprising at least two parallel threads of non-fuzzy fibrous material.

5. A sound-absorbing construction for ceilings and the like, comprising spacing members of equal thickness secured to said ceiling, sound-absorbing material positioned adjacent said ceiling and a facing membrane for sound-absorbing material consisting of woven threads of smooth material spaced apart to provide interstices and secured to adjacentspaciug members to form a panel, said woven threads, of themselves, lacking suflicicnt stiffness to maintain said panel as a flat surface but stiffened to prevent sagging whereby a series of said panels lie in substantially the same plane.

6. A sound-absorbing construction for ceilings and the like, comprising spacing members of equal thickness secured to said ceiling, a facing membrane consisting of woven threads of smooth material spaced apart to provide interstices and secured to adjacent spacing members to form a panel, said woven threads, of themselves, lacking suficient stiffness to maintain said panel as a fiat surface but stifiened to prevent sa ging, z whereb a series of said panels lie in su stantially t e same horizontal plane and sound I I 5 absorbing material supported-by said panels.

In testimony whereof, I have subscribed my name.

- HOWARD F. WEISS. 

